We have been running Zenworks forever.
I have Policies setup for all users based on what group they belong to.

In one school out of 12 (so in only one OU out of 13 OUs) The students DLU
policy does not work. If I associate a user directly to the student policy
DLU still does not work.

If I remove the user (student) from the student group and place the user
into the Staff group, DLU works fine. So I deleted the student policy
object and created new moved the sutdent back... but still does not work.